An aircraft tractor of such a construction is described in French printed application 2,452,427 (see FIG. 4) in which the fork within which the nosewheel of the aircraft is received is journaled on a lifting platform at the front end of the vehicle or tractor. The ramp on which the nosewheel is led into the recess of the fork is likewise pivotally mounted on this platform.
This construction has numerous disadvantages. For example, the pressing of the ramp by the wheel against the ground applies significant stress even at low speeds of the vehicle and can damage the ramp or the ground surface.
It is difficult to control the passage of the ramp below the nosewheel or the nosewheel onto the ramp and into the recess because the operations require high vehicle power, and control of the tractor during operations at such high power is difficult.
A further disadvantage is that during the pickup of the nosewheels by the ramp, a tilting moment can be applied to the vehicle which tends to lift the front wheels and interfere with control of the vehicle or require additional ballast and or a movement of the engine of the tractor forward.